 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.actions;

 import java.util.Iterator ;

 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.ui.IEditorRegistry;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.internal.ide.DialogUtil;
 import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;
 import org.eclipse.ui.internal.ide.IIDEHelpContextIds;
 import org.eclipse.ui.part.FileEditorInput;

 /**
  * Standard action for opening a system editor on the currently selected file
  * resource.
  * <p>
  * This class may be instantiated; it is not intended to be subclassed.
  * </p>
  */
 public class OpenSystemEditorAction extends SelectionListenerAction {

     /**
      * The id of this action.
      */
     public static final String ID = PlatformUI.PLUGIN_ID
             + ".OpenSystemEditorAction";//$NON-NLS-1$

     /**
      * The workbench page to open the editor in.
      */
     private IWorkbenchPage workbenchPage;

     /**
      * Creates a new action that will open system editors on the then-selected file
      * resources.
      *
      * @param page the workbench page in which to open the editor
      */
     public OpenSystemEditorAction(IWorkbenchPage page) {
         super(IDEWorkbenchMessages.OpenSystemEditorAction_text);
         setToolTipText(IDEWorkbenchMessages.OpenSystemEditorAction_toolTip);
         setId(ID);
         page.getWorkbenchWindow().getWorkbench().getHelpSystem().setHelp(this,
                 IIDEHelpContextIds.OPEN_SYSTEM_EDITOR_ACTION);
         if (page == null) {
             throw new IllegalArgumentException ();
         }
         this.workbenchPage = page;
     }

     /**
      * Return the workbench page to open the editor in.
      *
      * @return the workbench page to open the editor in
      */
     /* package */final IWorkbenchPage getWorkbenchPage() {
         return workbenchPage;
     }

     /**
      * Opens a system editor on the given file resource.
      *
      * @param file the file resource
      */
     /* package */void openFile(IFile file) {
         try {
             getWorkbenchPage().openEditor(new FileEditorInput(file),
                     IEditorRegistry.SYSTEM_EXTERNAL_EDITOR_ID);
         } catch (PartInitException e) {
             DialogUtil.openError(getWorkbenchPage().getWorkbenchWindow()
                     .getShell(), IDEWorkbenchMessages.OpenSystemEditorAction_dialogTitle,
                     e.getMessage(), e);
         }
     }

     /* (non-Javadoc)
      * Method declared on IAction.
      */
     public void run() {
         Iterator itr = getSelectedResources().iterator();
         while (itr.hasNext()) {
             IResource resource = (IResource) itr.next();
             if (resource instanceof IFile) {
                 openFile((IFile) resource);
             }
         }
     }

     /**
      * The <code>OpenSystemEditorAction</code> implementation of this
      * <code>SelectionListenerAction</code> method enables the action only
      * if the selection contains just file resources.
      */
     protected boolean updateSelection(IStructuredSelection selection) {
         return super.updateSelection(selection)
                 && selectionIsOfType(IResource.FILE);
     }
 }

